Gold(III) and nanogold interaction with Humic acids: Spectrophotometry, Capillary electrophoresis and mass spectrometric study
| Authors | |
|---|---|
| Year of publication | 2010 |
| Type | Article in Proceedings |
| Conference | 15th IHSS MEETING "Humic Substances and the Maintenance of Ecosystem Services", THE WORLD CONFERENCE ON HUMIC SUBSTANCES & NATURAL ORGANIC MATTER |
| MU Faculty or unit | |
| Citation | |
| Web | http://digital.csic.es/bitstream/10261/26346/7/VOL3.pdf |
| Field | Analytic chemistry |
| Description | It was found by spectrophotometric kinetic study that the reduction of Au(III) with HA is relatively fast in wide pH range. The redox reaction proceeds at least in two main steps and formed nanogold is stabilized in HA solution similar like with citrate but at elevated gold concentration a kind of {Aun, HA} aggregate is anyway precipitated. The interaction of nanogold with HA as studied by electrophoresis was found to be relatively weak. But the formation of several peaks indicates the complexicity of the reaction mixture. Mass spectrometry indicates that nanogold is forming adducts of gold with some low molecular weight compounds. Possible explanation is that supramolecular {Aun, HA} aggregates might be decomposed in the process of laser desorption ionization. Taking into account available literature data and the results achieved we can conclude that the both reaction of Au(III) with HA and interaction of nanogold with HA are quite complex. We suggest that reduction of Au(III) with HA goes in several steps via Au(III) and Au(II) and Au(I) to at least 2 different size of Aun clusters. Complexation reaction with Au(II) and Au(I) with HA fractions is not excluded. However, to prove that and to prove also possible formation of {Aun, HA}supramolecules needs further intensive research. |
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